Electric convection heater



Aug. 7, 1928.

H. N. SHAW ELECTRIC CONVECTION HEATER Filed Feb. 7, 1927 2 Sheets-Sheet l a 1N VEN TOR. A ji 2 B Y Liflfimdn 4T TOR/VF YE Aug. 7, 1928. 11,679,841

H. N. SHAW ELECTRIC CONVECTION. HEATER Filed Feb. 1927 2 Sheets-Sheet 2 INVENTOR.

' "A T TORNE Y5.

Patented Aug. 7, 192a.

UNITED "STATES HAROLD N. SHAW, OF MILWAUKEE, WISCONSIN.

ELECTRIC CONVECTION HEATER.

Application filed February 7, 1927. Serial No. 166,481.

This invention'relates to improvements in" electric convection heaters.

Ordinary electric heaters usually use resistance wire for heating units, and, because of the small diameter of the wire which must be heated to a high temperature for localized heat, it has not been use units of this character for heating large areas. Also, the ordinary resistance wire is heated to an incandescent state and there is always the possibility of inflammable material coming in contacttherewith and becoming ignited.

It is one of the primary objects of the present invention to overcome the before mentioned objections by providing an @1807 tric convection heater in which the resistance element is formed of a material of comparatively lar e surface area to transmit a larger amount 0% heat at a lower temperature than is common with ordinary resistance elemerits this low temperature also permitting the use of a shiny element surface.

A further object of the invention is to provide a convection heater in which the resist ance unit is formed of a thin strip or ribbon heated.

, A. further object of the invention is to provide an electric convection heater for air which has a relatively large heating area, but

' providb an electric heating element adapted to operate at a temperature near thatofthe air in the chamber being heated, which therefore changes in temperature as the chamber,

temperature changes, making possiblethe control of the chamber temperature by the use of a heating element having a suitable temperaturecoefficient of resistance and in series with which a suitable magnetic con-- trol switch may be used.

A further object of the inventionis to provide an electric convection heater arranged so that the heating'elements present a large ractical to area of heating surface with respect to the air path and a relatively'short path of travel for the air through the. heating elements. A further object of the. invention .is to provide an electric convection heater which is of very simple construction, is strong and durable, is etficient in operation, and is well adapted for the purposes described.

With the above and other objects in view the invention consists of the improved elec tric convection heater and its parts'and combinations as set forth in the claims and all equivalents thereof. 4

In the accompanying drawing in which the same reference characters indicate the same parts in all of the views:

Fig. 1 is a plan view of the improved electric convection heater Fig. 2 1s a side VIQW' thereof;

Fig. 3 is a sectional view taken on line 3--3 of Fig.2; Fig. 4 is an enlarged detail side view of one of the insulator brackets v,used in the heater; I 1

Fig. 5 is an edge view thereof; Fig. 6 is a sectional view of a casing showing the arrangementof several heating units 7 I therein;

F 1g. 7 is a sectional view illustrating as a modlfication. a shallow type casing and heating units therein for Wall or oven use;

Fig. 8 IS a sectional-view of another modified type of heater for well use;

. Fig. 9 is a sectional view of a ca"ing'and heating units therein disposed below a ve-' hicle seat; t. Fig. 10 is an illustration of a type of heater adapted to be positioned below a floor line;and

Figs. 11 and 12am enlarged fragmentary detail views showing the connector means employed between the circuit wires and the ends of the resistance elements.

Referring now more particularly to the drawings it will appear that the numeral 12 indicates a frame of triangular shape in 1 cross-section. Each inclined face of, the

frame is provided with rows of. insulator brackets 13. One of said brackets 13 is' shown in detail in Figs. 4 and band it will be seen that it is formed with opposed- 19 extended through face and of comparatively considerable the drawing I portion of the resist 1 Width with reference to resistance Wire used in standard practice and is Wound spire-Hy and of a diameter ccinperetiveiy large throughout its length, as cieeriy shown in As shown cleer il 3 each resistance is eztenceo diroue'h s,

a p iv n horizontal row oi rear recesses in horn zontal row of brackets 18 ongitndinaliy of the side of frame, e t1 frame the eieinent is ant mo n. d 1;- tended longitudinaiiy hrough ne edg esale; hracltcent horizontal row of recesses iii ets, and so 011. v

The free ends each resistance element are attached to circuit of connectors shown de i 12. Each connecto comprises tion of brass pipe r serted through the I e i brackets thm ead gso locie ing bracket 31?) is then i c u. in recess over the pipe and the end po tions of the bracket 39 engage the of bracket the locking bracket and into the the end portio I the circnit Wire 8? also engaged and stamped e57 said screw.

it 'Wlil thus e een heater ar anged as described presents a iarge heating area is req 12 formed i indicated at 93 8 is for end 3 is M. sided feet 2 in N ,Fig. 6 illiistl' ates at right engies tothe Jitllh of the e heing heated and'th'e path or through heating elements comparatively sheet In practice, the resistance elements are not heated to tempera so high to tend toward discoloration The in a casing Wt:

frames I sistance ei' scribed upper also the hot wt 4 moire i.

has perforations 29, The arrows show the course of the cold air into the casing and also the exit he bested air after it has passed over the heating elements In Fig. 7 a casing end heater thereinfor mounting in a Wait recess is illustrated, The casing 30 is of a sheilow type and the resistance element 22 is mounted therein on insn: later brackets carried by a frame 31. ilhe front of the casing is covered by a screen 28" or other perforate material and the cold air enters the lower portion thereof, circulst ing as indicated by the arrows, and around deflector plates 3a,

A. deep type Wait casing 30 is shown in Fig. 8 and 21 frame of triangular formation to support the heating elements is met t ed therein, This type heater presents a larger lies-sting than t iat shown in Fig, '7. i

The

er insy eiso he used cm; and "other email seated nd as shoe-min Fig. 9 21. cosing having perforate bottom and side Walls is mounted heiow seat 33 and shove the door carrying the resistance elein coure disposed Within the casing the door easing the end portions of lee iterate top pesscs one: e resistance and then rises through the inediei joot '"ion a, t1 6 cc 1 i i m "in 1 in t io ioregoing csciiption it will be seen that 1/ is improved electric convection heater is of e: e and not oi construction, and is Weii adapted for the pnrposes fortliq What K ciairn 211' ir entice is:

I An electric come in ring triangular frame cstried by opposite the frame and spi nioi'anted on the on o. s iongitn v.1 heater;v compris insulating I ineiine i i resistance ellernent ach side tees c forthsaid resists ee elements heir g modified "from stsnderd "'ice Toy substantial increase in Width end substantial LCitifitlbi in the the in s I; 1 l spiral to provide ce M and engaging the circuit wire and resistance 2 ports havm opposed recesses, a pm exten to a the frame, and an elongated spiral resistance element extending back and forth through elements having a shiny non-radiating surface, circuit wires, and connections between said clrcuit wires and the free ends of said resistance element, eachconnection comprising a metal pipe surrounded by an end portion of the resistance element and enga ed by a support, a locking bracket overlying pipe and engaging the support, and a stud extending through the bracket and pipe element. 4

4, An electric convection heater, comprlsmg a frame of triangular shape 1n cross:

section, a plurality of'insulating supports mounted in rows on the o posite side msaid supports havcooperatinfi lockt esupclined faces of the frame ing opposed, recesses and ing means, a pin extending through ports in a row and through the frame, an elongated spiral shiny resistance element mounted through the recesses of the su orts on each side of the frame and exten mg back and forth longitudinally of the frame, circuit wires, and connectors between ing a metal pipe surrounded by the end or-.

the pipe and engaging the support, and a.

said circuit ,wires and thefree ends of the resistance elements, each connector-comprisas tion of the resistance element and lodge in 7 a support recess,alocking bracket overlying stud extending through the bracket and pipe and engaging the circuit wire and resistance element.

a 5. An electric convection heater, comprissupsll v ing a frame, a plurality of insulatin ports mounted in rows thereon, sai

mg throng the supports in a'row and through the frame, and an elon ted s iral r.esistance element extending bee and orth through said support recesses. t In testimony whereof, I afiix my signature. 1 e

- HAROLD N; SHAW. 

